This invention relates to a synergistic combination of selected microbicides having greater activity than would be observed for the individual microbicides.
In some cases, commercial microbicides cannot provide effective control of microorganisms, even at high use concentrations, due to weak activity against certain types of microorganisms, e.g., those resistant to some microbicides, or due to aggressive environmental conditions. Combinations of different microbicides are sometimes used to provide overall control of microorganisms in a particular end use environment. For example, combinations of 2-methyl-4-isothiazolin-3-one and other biocides are disclosed in U.S. Pat. App. Pub. No. 2004/0014799. However, there is a need for additional combinations of microbicides having enhanced activity against various strains of microorganisms to provide effective control of the microorganisms. Moreover, there is a need for combinations containing lower levels of individual microbicides for environmental and economic benefit. The problem addressed by this invention is to provide such additional combinations of microbicides.